Variable condenser



May l0, 1932. w. s. KELLOGG VARIABLE CONDENSER Filed Sept. 24 1927 3 Sheets-Sheet May 10, 1932 w. s. KELLOGG VARIABLE ,CONDENSER Filed Sept. 24, 1927 3 Sheets-Sheet 2 Mk nl mm1 4/ 2,4. ln um..

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May l0, 1,932. w. s. KELLOGG VARIABLE CONDENSER Filed sept. 24.

1927 3 Sheets-Sheet 3 titl retreated May 1o, 1932 itil S. KELLGG, 0F PEOREA, L'ZLLNGS; HART .ist

@lill Application nleil September 24 192'?. io. lfltl.

llhis invention pertains to improvements in 'variable condensers.

, in object of the invention is to provide a condenser which includes a plurality ot rotor plates and stator plates wherein the several plates of said rotor plates may be operated serially throughout the entire number they control means in the hands of the operaor.

Another object is to provide a condenser having a plurality oi stator plates and rotor plates whereinisaid rotor plates are capable of operation independently of one another serially by an operating means common to all oit' them., said means adapted for engaging olf any one plate and carrying it into full mesh with the stator plates'and then leaving it to engage a succeeding plate tor a like action.,

.il further obiect is to produce a variable condenser which besides including a series ot rotor plates capable olf independent operation, also includes an operating means progressively movable through the condenser to directly engage each plate in its order to carry the same wholly into mesh with the stator plates, or out of the same, throughout 'the entire series, and disengage from each plate as that action is accomplished.

Still another object is to provide a variable condenser wherein its rotor plates are movable independent-ly of one another, and to furnish. means for turning one or more of the plates in successive order into mesh with the stator' plates, said means progressively movingi` through the condenser and in-sucn movement engaging a plate., turning it through its Jfull movement., then disengaging from. it and passing on to the next throughout the series.

il still further object is to provide tor a variable condenser having` independently movable rotor plates an operating means to actuate each plate in turn whereby sub- `3 stantially the capacity required 'tor a. given wave length results by the intermeshing of a required number ot plates followed by the partial intermeshing of a further single olate to obtain perfect resonance.

Again, an object is to provide a type of oi' dial movement Jfor a radio variable condenser combining a Vernier portion for exact tuning.

in addition to the obj ect above set forth the invention pertains to certain details of construction and arrangement of parts in a radio condenser of the variable type to be understood from the following description aided by the appended drawings wherein- Figure l is a plan of my improved condenser. f

Figure 2 is a side elevation of the same.

ligure 3 illustrates parts of the condenser in perspective.

Figure Llis a plan ot parts ot said condenser with portions shown in transverse section.

Figures 5 and 6 are elevations of a spacing member or washer to lie between the rotor plates of the condenser.,

Figure 7 is a plan of parts shown in Figure l greatly enlarged.

Figures 8 and 9 are respectively a plan and end elevation ot a spiral gear shown in *Eigures l and 7 produced on a scale corresponding to that in said Figure 7,

Figure l0 isan elevation ot a form ot dial usable with the condenser of the type herein.

'Figure 1l is aplan ot a dial arrangement ot a preferred form for use with my condenser.

Figure 12 is an elevation oi" the same.

Figure 13 is a transverse section ot parts of said dial arrangement on line 13-13, Figure l2.

Figure 1d is a detail of parts of the dial mechanism as seen in iront elevation., and

digure l5 is a transverse section ot parts ot the dial mechanism and the panel ot a radio set.

l am fully aware of the tact that there is no novelty in separately mounting and operating the rotor plates ot a condenser but in so 'far as l am informed it is new to furnish mechanism operated by a dial-knob for successively carrying these plates into or out ot liti mesh with the stator plates, picking up one plate and turning it through its full movement and then leaving it to pick up the next. It is believed to be novel, also, to employ such mechanism to turn one or more plates to substantially the point of resonance of a radio receiver followed by the partial movement of another plate corresponding to a vernier adjustment for exact resonance, this being one of the purposes of my invention.

The condenser herein may be shielded and in conformity therewith a metal case is provided made up of a cylindrically curved lower one-half 1 and parallel side walls 2, and an upper one-half 3, Figure 2, to engage with said lower half andsecured by screws 4 for example.

Lying between said walls 2 and secured at their ends thereto in suitable manner are two members 5 of insulating material between which is suspended a series of stator plates 6 y in any usual manner, there being'a metal cross member 7 connected to all of said plates from which extends a binding screw 8 insulated from the case, while a similar connection for grounding is provided at 9 on the .said case 1, 2, Figure 1. A

Extending centrally through the condenser space and secured to each wall 2 by the connection 9 and screw 10, for example, is a rod 11, Figure 4, overlying which is a tube 12 having a slot 13 therein extending lengthwise thereof, Figures 4 and 5.

The rotor plates of the condenser are denoted at 14. Each includes a central portion 15, Figure 3, having on its edge a series of teeth 18 in a semi-circular arrangement, Figure 2. Said portion 15 is provided with a hole 17 in the center from which all of the teeth 16 are equidistant, said hole being of a diameter to just receive the tube 12 in a smooth turning fit. The plates are adapted to slip upon said tube 12 spaced whereby each may pass between two of the stator plates G as in common practice. However, said plates are spaced from one another the required distance bythe interposition of washers 18, Fig-- uresb and 6. each being prevented turning on the tube 12 by including a key-portion 19 to engage in the slot 13, but any equivalent method may be employed. Since the plates v the desired spacing of the plates results. At

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the back of the condenser a sleeve 2() may be placed over the tube 12 between the side 2 of the case 1, 2, and one of the washers 18, Figure 1, to form an abutment for the series of plates and washers, while at the front of such condenser a spring 21 may be interposed between the said series and the front side 2 of the condenser case thereby keeping all of the members ot the group in snug order preserving the exact spacing of the plates.

Having thus vmounted the plates, by which to operate 'them independ is provided to be understood from the following:

Extending between the plates 2. oi the case and projecting through the front one thereot is a threaded rod 22, which. iuay be termed a thread-bar, secured to the back plate by nut 23, as an example, said rod being held thereby from rotating. Qverlying or euclosing the rod is a tube 2-1- slotted at 25 throughout, said tube likewise extending through the iront plate of the condensercase, 'both the rod and tube likewise extending through 'the supporting panel 26 and a dial plate 25', the tube receiving upon it the dialing knob 2? secured thereto in any suitable manner., Said tube is held in place against the back plate 2 of the case and prevented having endwise movement by a screw 28 which engages in the end of the threadbar 22 within the knob 27, the screw-head abutting upon said tube. Sleeved on the latter is the hub 29 of a spiral gear whose spirally arranged teeth are denoted at 30. rl`he hub carries a pin 31 which extends through the slot 25 of the tube 24 'to engage between two of the threads o: the threadbar 22.

It is clear that in rotating the tubel 24 on the fixed thread-bar the gear :2S-)#30 rotating therewith will be carried along said tube due to the pin 31 following the threads of said thread-bar. l/Vhen all oi the rotor plates are fully 'disengaged from the stator plates the gear 29, 30 lies close to the front plate 2 free oil all ol' the said rotor plates. Clockwise turning of the knob 27 advances the gear along' the tube to cause it to mesh with the first plate. The relation ot 'the teeth of the plate and gear, and the lead of the threads ot the thread-bar is such that when the plate has been carried into full mesh. with the stator the terminal tooth of said gear disengages from the teeth of the plate and the leading tooth of the gear has advanced into position to engage the teeth of the second plate, the described operation being repeated throughout the entire series of rotor plates, and obviously a counter-clockwise rotation of the knob 27 will reverse the operation 4fully discngaging the plates in the reverse order one by one.

When a. number of plates are in mesh with the stator giving a certain capacity corresponding substantially with a given wave length it is clear that tuning to complete resonance can be accomplished by a partial movement of an additional plate for a required small additional capacity with great exactness and an exactness not possible with essaies any condenser of which l am aware. That is to say', by reason of the tact that l am enabled to operate each and every rotor plate by direct control through a dial-knob and the gear 29, 30, or its equivalent, an enact= ness of adjustment is assured.

A multiple condenser such as a three condenser, for example, may be constructed by coupling several oi' the tubes together or by using a single tube extending through all of the condenser bodies, this not having been shown however, and the t* ring can be accomplished. But the advantage of my method ot' operation in connection 'with such gang arrangement will new be evident. ln order that the capacities ol oi the condensers of the gang may be idf itieal so that loggings of the several dials o a radio set Willcorrespond, one oi; the plates et any condenser may be advanced by hand a distance of one or more teeth, or to such position, at least, that the several capacities will agree and there lett, the spiral gear picking up the plate in its regular travel through the `condenser' but always leaving it in the hand-adjusted position after each operation thereo.

Due to the tact that the dial-knob in my condenser must turn through. a plurality oi rotations, in this instance a complet-e revolution to a one-half rotation ot a rotor plate, a type of dial is required over which to spread station readings. Therefore merely as shoviing a manner oi doing this the dial plate 25 previously referred to is carried on the tube 24 to rotate with it and the knob :27. ln its rear tace it may have a spiral groove 2'2" indicated in broken lines in Figure l0. lin arm 32 is pivotally mounted on the panel 26 and a pin 33 on its free end, Figure l, may engage in the groove, and an indicatonarin fixed With respect to saidarm 32 swings over the face of the dial describing a spiral path in the rotation of the latter and at the entremity ot which station readings be made. Pins 35 for example carried bythe dial serve as stops at the ends of dial rotation, the same adapted to abut upon said arm 34.

ln Figures ll to l5 the preferred form of dial arrangement is shown, hon/ever, Wherein, as before, 26 designates the panel for supporting the condenser. And in this instance 'the latter by choice has been rotated to the right sufficiently to station the knob 277' at the bottom of the dial 36, this being merely for appearance sake.

Said dial consists of a ring `which rotates upon or about a disc 37, for example, secured on the panel 26. The inner edge oic the ring isprovided 1with equally spaced notches 38 to separately receive a pin38 carried by the said knob 27 which pin acts after the inanner of a gear tooth by entering a notch 33 in each rotation of such knob. The disc 37 is cut away at 37 to permit the orbital movenient et said pin 38. A cover-plate overlies the dial 36 and is also cui', away at 36 tor the same reason as inst given, while screws l() may extend through the cover-plate and disc into the panel 26 securing the parts in place. rlhe tube 2li Vand thread-bar 2 2 extend through the cover plate and receive the said knob 2?. the latter covering the openings 3o and 3i. 'llhe knob carries any usual portion 272 which may be provided with indicating marks extending entirely around it numbered trom O to 100, as example, any mark being brought opposite a mark 41 on the coverplate 39. ln the latter is a Window Li2 through which station indications on the dial 36 may be read, and said indications may represent' meters or station signatures.

ln operation, one full rotation oi the knob will advance the dial one position opposite the Window 42 due to the engagement of the pin 33 with one oit the notches 38. llt is clear that one lull rotation oi the knob will impart a iull onehali2 turn to any plate il added to which, a station having been partially brought in by that movement of the plate, a further turn ot the knob will advance a succeeding plate to a point ot full resonance whereupon the reading Will be at both the Window d2 and at the knob answering admirably as a Vernier dial arrangement.

The station indications or meter readings may entend entirely around the dial, i. e., in a iuil circle, this depending upon the number of rotor plates employed and the rate oi advance oi the dial through the pin 38'. That is to say, the rate of step by step ad vanccment oi the dial hinges upon the distance said dial travels at cach engagement oi said pin. @therwise stated, as the pin more closely approaches the center of knob rotation the less distance oi travel will be imparted to the dial.

l claim:

l. ln a variable condenser, in combina tion vvith the rotor thereof whose plates are independently movable, mechanismincluding a member mounted to travel substantially parallel to the axis of mounting oi the plates adapted to engage with and operate each plate independently and in successive order and after each such operation disen` gage therefroi 2. :a a variable condenser, in combination with independently movable rotor plates, mechanism including a member adapted to advance through the condenser substantially parallel to the anis of mounting of said plates, and adapted to positively engage and transmit movement to a plate and then disengage therefrom before engaging a succeeding plate.

3. ln a variable condenser, in combination with independently movable rotor plates,

mechanism including a member mounted for cessive order both into and out of mesh with said stator plates.

5. In combination With the stator plates and the independently rotatable plates of a variable condenser, mechanism including a member mounted for progressive movement in a direction paralleling the axis of said rotatable plates adapted to engage and operate each plate independently and in successive order into mesh with the said stator plates in one direction of movement of said member, and to unmesh the same in a reverse direction of its movement.

6. In combination with the stator plates and independently movable rotorplates of a variable condenser, mechanism including a rotatable toothed member mounted for movelnent progressively through the condenser in a direction substantially paralleling the axis of mounting of said rotor plates, the said rotor plates each having teeth adapted to be successively and independently engaged by the member whereby to turn said plates independently and in successive order into mesh. with the stator plates.

7. In combination with the stator and independent-ly movable rotor plates of a variable condenser, a rotatable toothed member mounted for movement progressively past said rotor plates, a series of teeth on each ofthe latter, the teeth of one of the described elements being spirally arranged, and means manuallyfoperated to advance the member through said condenser.

8. In combination With the stator and independently movable rotor plates of a variable condenser, means mounted for progressive travel through the condenser in a direction at right .angles to the planes of the plates adapted to positively engage and carry said rotor plates independently and in serial order into mesh with the stator, and also adapted to disengage from each rotor plate in succession after such meshing.

9. In combination with the independently movable plates of a variable condenser, a member mounted for progressive movement through the condenser in a direction at right order and to disengage from one plate before engaging a succeeding one.

l0. In combination with a series of independently movable rotor plates in a variable condenser, each said plate having a series of teeth disposed thereon in a semi-circular line, a rotatable toothed member, a mounting for said member adapted to carry the same progressively through the condenser,l

said member adapted to engage and operate each plate in successive order and to disengage from one before engaging the next.

ll. In a radio condenser, the combination of a pair of spaced rotatable condenser plates mounted on a common axis, each having a series of teeth arranged concentrically of said axis, a sleeve having a series of teeth ar(- ranged thereon in a spiral adapted to engage the teeth of the plates, and a mounting for the sleeve adapted to advance the latter in a line paralleling the said axis of the said plates.

12. In a radio condenser, the combination of a pair of spaced independently rotatable condenser plates mounted on a common axis and each having a series of teeth arranged concentrically of said axis, a sleeve having a series of teeth arranged about the same and engageable with the teeth of the plates in serial order independently, and a mounting for the sleeve adapted to advance the latter in a line paralleling said axis of said plates.

13. In combination with a series of independently rotatable rotor plates in a variable condenser, each plate having a series of teeth disposed thereon in a semi-circular line, a mounted threadbar extending through the condenser, a tube enclosing the thread-bar and Vhaving a slot extending longitudinally thereof opening upon said thread-bar, a toothedmember carried by the tube rotatable therewith and engaging thethread-bar adapted in the rotation of the tube to move through the condenser and engage the teeth of one of the plates and also adapted after imparting a full turn to said plate to disengage there from.

14. In combination with a series of independently rotatable rotor plates in a variable condenser, each plate having a series of teeth disposed thereon in a semi-circular line, a mounted thread-bar extending through the condenser, a tube enclosing the thread-bar and having a slot extending longitudinally thereof opening upon said thread-bar, a member carried by the tube rotatable therewith. having teeth thereon, arranged in a spiral, said member engaging the thread-bar through said slot, said teeth of the member adapted in the rotation of the said tube to travel progressively through the condenser and to engage the teeth of one of the plates and also adapted after imparting a full turn to said plate to disengage therefrom,

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15. In combination with a. series of independently rotatable rotor plates in a variable condenser, each said plate having a series of teeth di osed thereon in a semi-circular line, a threadar extending throu h the condenser fixed with respect to the ody thereof, a tube enclosing the thread-bar adapted to rotate thereon and having a slot extending longitudinally thereof opening upon the threadbar, a toothed member encircling the tube adapt-ed to mesh with the teeth of the rotor plates, said member engaging the thread-bar through said slot, and an operating dial-knob fixed on the tube.

16. In combination, a thread-bar, a member paralleling the same and rotatable about it, a sleeve having a projection to engage the threads of said thread-bar, means to prevent the sleeve and member from rotating relatively. but permitting said sleeve to move l longitudinally of the latter, both the sleeve and member adapted to rotate together with respect to the lsaid thread-bar.,

17. In combination, a thread-bar, a tube enclosing the same having a slot extending longitudinally thereof opening upon the thread-bar, and a toothed sleeve encircling the tube engaging the said thread-bar, the tube and sleeve adapted to rotate together with respect to the said thread-bar.

18. In combination, a thread-bar, a tube encircling and rotatable about the same and having an opening extendin along one side thereof, a toothed sleeve encircling the tube, and means on the sleeve extending through the opening of said tube and engaging the said thread-bar, the tube and sleeve adapted to rotate together with respect to the threadbar, and said sleeve adapted to move longitudinally of both the tube and thread-bar.

19. In combination with independently movable rotor plates of a variable condenser, a member mounted for rotative movement progressively through the condenser in a di rection at right angles to the planes of said plates adapted and arranged to positively engage and impart rotative movement to each plate in its order and to disengage from. one plate before engalging a succeeding one.

In testimon w ereof I aliix my signature.

%V'1LLIAM S. KELLOGG. 

